In loading and unloading of a truck parked at a conventional loading dock, it is essential from a safety standpoint that the truck be effectively secured in place against the front wall of the dock so as to prevent accidental movement of the truck away from the dock while mechanical devices, such as dollies, fork lift trucks and the like, are moving between the parked truck and the loading dock platform.
Heretofore to effect securement in place of the parked vehicle, various methods have been utilized, such as (a) chocking the rear wheels of the parked vehicle; (b) chaining the rear end of the vehicle to a stanchion or ring provided on the dock; or (c) engaging a mechanical restraint, such as a hook mounted on a dock front wall with an ICC bar required to be carried on the underside of the vehicle. The ineffectiveness and short-comings of these approaches are well known. In chocking, for example, the securement depends upon the driver or dock personnel exercising care and patience in inspecting and clearing the driveway surface adjacent the dock of ice, snow, oil or debris so that the chocks can be properly positioned without slippage against the rear wheels of the parked vehicle. Where chaining is involved, it is imperative that the chain or cable connecting the vehicle to the dock be made taut. Because of the inordinate amount of time and labor involved in performing such chaining this method is not widely adopted.
Prior mechanical restraints, on the other hand, while in many instances overcome the aforenoted problems associated with chocking and chaining, they are nevertheless oftentimes beset with one or more equally serious short-comings, such as: (a) they are of a costly, complex and bulky construction; (b) they require substantial structural modifications and changes to be made to the dock itself; (c) they require an electrical, hydraulic and/or pneumatic power source; (d) they require an inordinate amount of servicing and maintenance; and (e) they are incapable of properly accommodating a wide variety of ICC bars.